The present invention is directed to an outsole. More particularly, the present invention is directed to a golf shoe having an improved outsole that enables greater torsional movement and flexibility of the shoe.
Historically, people first wore shoes to protect their feet. Over the centuries, footwear evolved into many different types that were specific to particular activities. Thus, the protection offered by a cold-weather work boot is highly different from that offered by a running shoe. In addition to protecting the feet, athletic footwear has further developed to offer specific functions dependent on the particular sport. Soccer shoes, for instance, have spikes for traction, whereas cycling shoes have very stiff soles with mounting plates for cleats to engage the pedal. In this manner, golf shoes have evolved to provide the wearer with good traction on grass, comfort while walking, and a stable platform for hitting the ball. Typical golf shoes thus have a relatively stiff sole with metal spikes or plastic cleats.
A stiff sole, while providing a stable platform, can nonetheless cause discomfort because there is a balance between how the foot should be allowed to move versus how it should be supported. An example of this is the fact that during walking and at the start and finish of the golf swing, the foot bends at the metatarsal joints (the ball). Aside from the physical effort needed to flex a very stiff sole (which would tend to cause a xe2x80x98clunkyxe2x80x99 gait as when wearing clogs), sole stiffness tends to cause the heel of the foot to slide up and down in the heel cup, potentially causing blisters. Thus, golf shoes have evolved to have soles that flex across the ball area to allow this movement without compromising the lateral stability of a good hitting platform.
Relatively recent studies in biomechanics have sought to better quantify how the 26 bones of the foot move relative to each other during human movements. One particular motion that has been identified is a torsional movement about the long axis of the foot. In effect, the forefoot and rearfoot twist relative to each other. It is thought that this movement smooths the contact between foot and ground, decreasing impacts with the ground as well as providing better ground contact. This observation has led to the development of a golf shoe sole to allow this natural movement.
U.S. Pat. No. Re. 33,194, reissued from U.S. Pat. No. 4,608,970, to Marck et al. discloses an orthopedic device for correcting infants"" feet. The device includes a posterior part, an anterior part, and a ball-and-socket for allowing three degrees of freedom between the posterior and anterior parts during set-up. These parts are immobilized in a particular position, when the device is in use. As a result, this device does not assist with the natural torsional-like action of the foot in walking where such action is missing.
U.S. Pat. No. 3,550,597 discloses a device that facilitates the natural rolling action of the foot during movement by providing a flat construction with front and rear main lifting sections rigidly connected to a resilient intermediate section that is twisted into the form of a flat torsion spring. The device applies a yieldable torsional action during use that is applied to the foot by the lifting sections, whereby the heel of the foot is urged upwardly at the inner side and the forefoot is raised upwardly at the outer side, producing a torsional action similar to the natural torsion action of the foot.
Another construction intended to provide greater support to the wearer of the shoe is disclosed in U.S. Pat. No. 5,243,776 to Zelinko. The Zelinko golf shoe has a sole having a forward end, a heel end and an intermediate portion joining the two ends. A spike support plate is journaled to a post extending from the forward end of the shoe. The spike support plate is so mounted to the forward end for rotation about a vertical axis. A biasing means, such as tension springs, is provided to connect the spike support plate to the heel end and for constantly biasing the spike support plate to a neutral (i.e., non-rotated) position and returning the support to that position after the support has been rotated. A cover is provided to protect the biasing means. The Zelinko golf shoe is constructed to allow the forward end of a golfer""s foot to remain fixed during a golf swing while the heel rotates.
There remains a need for an improved outsole for a shoe that enables individuals movements of the foot, particularly, the rotation between the rearfoot and the forefoot. By allowing and controlling these rotations, the outsole would resists torsional instability during play, provides independent traction suspension, and increases the flexibility of the shoe to accommodate the movement of the wearer.
The present invention is directed toward an outsole for a shoe construction having a forward portion, and a rearward portion, coupled together at a pivot point. The forward and rearward portions are operatively connected to freely allow independent and relative movement of the forward and rearward portions about the pivot point. This relative movement may occur during a user walking with the outsole or swinging a golf club.
In another embodiment, the outsole further comprises a first axis extending substantially longitudinally across the outsole and through the pivot point and the forward and rearward portions are moveable about the first axis. In yet another embodiment, the outsole further includes a second axis extending through the pivot point and offset with respect to the first axis and the forward and rearward portions are moveable about the second axis. In one embodiment, the second axis is offset at an angle between about 5xc2x0 and about 30xc2x0 and in another embodiment the pivot point is positioned adjacent the exterior of the outsole.
In one embodiment, the forward and rearward portions may be operatively connected discrete pieces. In another embodiment, the outsole may include a ball-and-socket connection configured to allow relative movement of the forward and rearward portions.
In yet another embodiment, the present invention is directed to a shoe comprising an outsole and an upper generally configured to accommodate a foot connected to the outsole. The outsole includes a forward portion for supporting the forefoot of a foot and a rearward portion for supporting the heel of the foot. The forward portion defines a chamber. The rearward portion includes a protrusion. The forward and rearward portions are operatively connected when the protrusion is received in the chamber.
In another embodiment, the present invention includes an outsole comprising a first piece, a second piece separate from the first piece, and a flexible member joining the first piece to the second piece. The flexible member includes a length that is less than the length of each of the first and second pieces. Furthermore, the material of the flexible member is substantially softer than the first and second piece materials.
In such an outsole, the first and second piece materials may have a Shore A greater than about 75 and the flexible member material may have a Shore A less than about 85. In addition, in such an outsole the first and second piece materials may have a Shore A greater than about 85 and the flexible member material may have a Shore A of about 70.
The present invention is also directed to a sole construction comprising an outsole having a transparent window member on the upper surface thereof, a midsole for connected to the outsole, and a gel cushion between the outsole and the midsole. At least a portion of the gel cushion may be aligned with the window member.